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The numerical investigation of bioconvective nanofluid (NF) flow, which involves gyrotactic microbes and heat and mass transmission analysis above an inclined extending axisymmetric cylinder, is presented in this study. The study aims to investigate the bioconvection flow of nanofluid under the influence of heat sources/sinks. Through proper transformation, all partial differential equations are transformed into a non-linear ODE scheme. A new set of variables is presented in the directive to get the first-order convectional equations and then solved numerically using bvp4c MATLAB, embedded in the function. The proposed model is validated after calculating the error estimation and obtaining the residual error. The influence of various factors on the velocity, energy, concentration, and density of motile microorganisms is examined and studied. The analysis describes and addresses all physical measures of concentration such as Skin Friction (SF), Sherwood number, the density of motile microorganisms, and Nusselt number. To validate the present study, a comparison is conducted with previous studies, and excellent correspondence is found. In addition, the ND-Solve approach is utilized to confirm the bvp4c. The mathematical model is confirmed through error analysis. This study provides the platform for industrial applications such as cooling capacity polymers, heat exchange, and chemical production sectors.

This study explores heat transfer behaviour in mixed convection of a fluid with internal heat generation, a situation found in chemical and nuclear engineering contexts. Computational fluid dynamics is used to simulate laminar ascending mixed convection flow of a heat-generating fluid in a vertical cylinder with uniformly cooled wall, based on a liquid nuclear fuel concept. A new non-dimensional parameter, the IHG-flux number Ω, is developed to express the balance of axial convection versus radial conduction heat transfer. It was found that heat transfer behaviour depends on this parameter, and it can be used as the transition criterion to categorise the simulated results into three distinct heat transfer regimes. A heat transfer correlation using Ω was also developed for Regime I with small values of Ω, where convection and conduction effects are balanced in a stable flow. In Regime II at intermediate Ω, stronger convection gives rise to flow instability. In Regime III with large Ω, convection dominates and the temperature profile inverts so that the maximum temperature occurs at the wall, while instability remains likely.

Abstract With the present policy stance of the UK government, the rate of extraction of North Sea oil becames one of the more important instruments for managing the economy in the 1980s. In this paper the effects of different depletion policies are examined, ranging from rapid early extraction to a low profile long-term conservation policy. The author explains how the depletion policy should be seen in the context of the UK economy and present government policies. He describes four possible depletion policies for the 1980s, together with the assumptions which are made in analysing their effects. The macroeconomic results of putting each policy in the Cambridge multisectoral dynamic model are presented and show the severe short-term costs of unrestrained production. Finally relations between depletion policy and de-industrialization are examined.

Oil palm plantations have expanded rapidly in recent decades, and are causing substantial impacts on tropical habitats and biodiversity. However, owing to its long lifespan (25-30 years), oil palm forms a much more varied and structurally-complex habitat than many other crops. This can include abundant understory vegetation and also epiphytes on palm trunks. However, the diversity of this plantation vegetation has been poorly studied, and there has been little consideration of the impacts of common plantation vegetation management practices on plant communities. We conducted a long-term vegetation management experiment that forms part of the Biodiversity and Ecosystem Function in Tropical Agriculture (BEFTA) Programme in Riau, Indonesia. We manipulated herbicide and manual cutting regimes within mature oil palm plantations to create three different understory complexity treatments (Reduced, Normal, and Enhanced vegetation) across replicated sets of plots. Plant communities were surveyed before and after experimental understory vegetation treatments began in three different microhabitats: within the middle of the plantation block (core), on the road edge (edge) and on oil palm trunks (trunk). Part of the sampling was also conducted during a drought event. We recorded 120 plant species, which comprised a mixture of native, non-native, ‘beneficial’, and ‘problem’ species. We found substantial variation in plant communities between edge, core, and trunk microhabitats, indicating high levels of heterogeneity within the plantation. There were significant effects of varying understory treatment within both core and edge microhabitats, but no spillover of impacts into the trunk microhabitat. We also observed substantial impacts of drought on plant communities, with declines in either biomass, percentage cover, or richness seen across core, edge, and trunk microhabitats during low-rainfall periods. Our findings highlight the diversity of plant communities that can be supported within oil palm plantations, and the substantial impacts that management decisions, and also drought, can have on them. Given the role that diverse plant communities can have in supporting species in other groups, this is likely to have a significant impact on the wider plantation biodiversity. We suggest that plantation management strategies give greater consideration to within-plantation understory plant communities and choose more wildlife-friendly options where possible.

AbstractClimate change effects along with anthropogenic activities present the main factors that threaten the existence of heritage sites across the north Nile Delta of Egypt close to the coastline of the Mediterranean Sea. Observing the changes in the landscape close to the archaeological sites is an important issue for decision‐makers in terms of reducing the negative impact of natural events and human activities. The coastal heritage sites are becoming strongly threatened by the rising sea level phenomena that will happen due to global warming. Focusing on the distribution of the archaeological sites, this study aims to detect the areas at risk of shoreline erosion or accretion in the northern shoreline of the Nile Delta. In this study, the changes in the northern shoreline of the Nile Delta were observed and calculated during the last hundred years based on the integration between the old topographic maps from surveys in 1900, 1925 and 1945, optical satellite images captured by Landsat in 1972, 1986 and 2000; Sentinel2 2021; and the Radar SRTM data. The results of this study showed that the changes were enormous with a great shoreline erosion process over the last 121 years recorded along the shoreline in the periods between 1900–1925, 1925–1945, 1945–1972, 1972–1986, 1986–2000 and 2000–2021. The areas eroded were about 5.3, 4.7, 5.6, 8.9, 2.5 and 5.4 km2, respectively. Such negative movements caused the loss of two heritage sites, and the expected changes will lead to the loss of additional heritage sites in the next 500 years. Furthermore, a model was suggested for protecting the coastal heritage sites threatened by the risk of submergence. This study can help the decision‐makers to detect the coastal archaeological sites at risk and create innovative solutions for protecting these irreplaceable heritage sites.

Using an in-house developed platform, the performance of an Arthrospira maxima biofilm photosynthetic microbial fuel cell (PMFC) was monitored both optically and electrochemically. Fluorescence (excitation wavelength 633 nm, emission range 640 to 800 nm for detection of fluorescence), power density and current output of the PMFC were recorded in real time. Confocal microscopy performed in situ allowed detailed fluorescence imaging to further improve the understanding of the photosynthetic activity of the biofilm that developed on the anode surface of the PMFC, whilst power and current outputs indicated the performance of the cell. The PMFC was shown to be sensitive to temperature and light perturbations with increased temperatures and light intensities resulting in improved performance. A direct relationship between the fluorescent signature and the amount of current produced was identified. With a decreasing external load and increasing current production, the biofilm attached to the anode electrode showed increased fluorescence inferring improved activity of the photosynthetic material. Furthermore, the imaging proved that viable cells covered the entire surface area of the biofilm and that the fluorescence increased with increasing distance (z axis) from the electrode surface.

AbstractMixed‐halide lead perovskites have attracted significant attention in the field of photovoltaics and other optoelectronic applications due to their promising bandgap tunability and device performance. Here, the changes in photoluminescence and photoconductance of solution‐processed triple‐cation mixed‐halide (Cs0.06MA0.15FA0.79)Pb(Br0.4I0.6)3 perovskite films (MA: methylammonium, FA: formamidinium) are studied under solar‐equivalent illumination. It is found that the illumination leads to localized surface sites of iodide‐rich perovskite intermixed with passivating PbI2 material. Time‐ and spectrally resolved photoluminescence measurements reveal that photoexcited charges efficiently transfer to the passivated iodide‐rich perovskite surface layer, leading to high local carrier densities on these sites. The carriers on this surface layer therefore recombine with a high radiative efficiency, with the photoluminescence quantum efficiency of the film under solar excitation densities increasing from 3% to over 45%. At higher excitation densities, nonradiative Auger recombination starts to dominate due to the extremely high concentration of charges on the surface layer. This work reveals new insight into phase segregation of mixed‐halide mixed‐cation perovskites, as well as routes to highly luminescent films by controlling charge density and transfer in novel device structures.